If your husband witnessed the whole scene, what did he do about it? What is he doing about his disrespectful, rude daughter?

If they can't be respectful in your home, your husband can either do something about it or see them elsewhere.

I wouldn't feel guilty because his kid is a brat. Yelling was probably not the answer but I know emotions run high when it comes to kids hurting animals or other kids.

If he wants to see his kids these are the terms. No abusing animals. And he should front up to his ex and explain "Lucy was hitting the dog in the face with a pillow and would not stop. HannahD rightly told her off and to stop doing it. Her rudeness when she is here is disturbing and frankly unacceptable. If she acted the same way around your partner I would have a fit. Now I cannot force her to come over however she should not be able to hide away at her other parents place whenever she gets in a pissy mood. If we were still together where would she run if she was angry with you? I am not siding with HannahD or Lucy but with the dog. It did nothing wrong. I expect to pick them up next time. Thank you."

One time my SSs went back to their mother bleating on about me making them take their hats off at the dinner table and not eating mashed potato with a teaspoon at the age of 14. She emailed my DH a looong complaint of my 'problems' (the one and only time she ever said anything) . DH sent her an email back telling her she was listening to one side of the story and if she is really so concerned she should call him and he can set her straight. Never another peep out of her. Although I heard she thought we would get divorced within a year of marriage. Meanwhile 14+ years later .......

I understand that you feel guilty because I think I would too, but the reality is that you should not feel guilty at all. You were protecting your innocent pet. Your DH witnessed it and should have yelled at her too. He should have also set it straight with BM about what happened. And, I know this is ideal, but BM should have been ok with your reaction or at least not ok with her daughter's actions. She should have been lecturing her daughter on how to treat animals when she heard what happened. It sucks that the skids don't want to visit, but BM's and DH's reaction should have been different. DH should have reprimanded her, so you should not feel guilty about being the one to do it. DH should have taken the brunt of this for his daughter's actions. He needed to back you up on this.

Ok, teen hit furbaby in face three times with a pillow. Dad sat there doing nor saying anything. One the third hit, you yelled at kid. (IMO, two hits late)

So what did you yell at teen? Was it along the lines of leave the dog alone, act your age et? Or was it 'touch my do again and I'll smack you all the way back to your mother's house?  (Nope, not accusing you of that , just trying to get to what your definition of 'yell' is).

How did the three kids leave the home (do they drive? Called Mom to fetch them? Demanded Dad take them?).

I see you and DH just got married less than two months ago. Don't feel guilty scolding the teen. She was hitting an animal. She was hitting an innocent animal right there in front of her father who said or did nothing.  So unless you went over the top crazy and shouting the brat was banned for life and to GTFO, meh, she's lucky all you did was yell an scold her.

I have zero tolerance for abusing animals. Even if it's not perhaps really hurting the dog. Poor little guy isn't use to having some snot kid hit him in face with a pillow and that certainly isn't playful fun for the dog. 

With all that said, I wouldn't fret over Dad not seeing his kids in your new home If he's just going to sit there witnessing his kids misbehave an say and do nothing, he can have his visitation outside the home. Let him take them to dinner out once a week an maybe a father/kid outing once EOWE. 

Why on Earth would you feel guilty about defending your pet against a violent toxic POS kid?

Stop that!

Maybe if your DH had actually maintained contact with his balls and parented his kids rather than catering to them they would not be so adept at running to mommy.

And.. why isn't he beating on BM's door with a copy of the CO in hand to drag them to visitation by a twisted ear?

Parents who abdicate their balls and position as parents to controlling spawn are wastes of parental skin IMHO.

smh.

No respect? Yeah, that would be my sign for calling it quits. It is the one thing I cannot tolerate. 

Your SD abused an animal  - she was lucky the dog didn't rightfully bite her. What kid of feral children are these? Your husband should count himself lucky with only not seeing his children. I would divorce him and be rid of his horrid children too!

that your DH talked with DSD about her rudeness towards you. I know you say you can kill her with kindness, but if she keeps this up, it's going to wear on you.